My 1996 grand prix started to register cooling temp of over 210 degrees. the motor doesn't seem to be overheating. I've replaced the water pump, thermostat, temp sensor, both fan relays, low coolant sensor and the fans still won't come on and the low collant light keeps coming on. Any thoughts on the problem?

I'll put my bets on a faulty gage...but that's just me.

Have you checked your cooling fan to see if it is working propely? Let the car idle and get warm and listen for the fan to kick in (if they are electric) or just watch to see if the fan starts to spin faster if it is the old school type with a clutch. Have you replaced the thermostat? A bad one will let the temp rise since it opens too late and then the temp will drop off. But it won't due this only at a light and it will do it infrequently.

indicates a head gasket problem
at idle the gasket is sealing but under load is allowing compression into water jacket
do a compression test
check cat converter for failure blocking exhaust
run fault codes to check for mixture control problems

First off when did this start? Was it prior to the Thermostat replacement or after? What was the purpose of relacing the tstat?

From my experience use only a high quality t-stat that maintains a constant temp. is the best solution, it's easy to try and save a few bucks I'm just as guilty as the next guy however I've had many years of experience in the automotive field, throughout the years I've replaced hundreds if not thousands of t-stats and all are not even close to created equal. My opinion is not to go to the big box stores to purchase an off branded t-stat these t-stats open very inconsistantly and tend to have temps that fluctuate greatly. Commonly these economy t-stats are rated at say 195 degrees however they tend to snap open and closed very fast and erratically causing the temp to suddenly drop and then snap closed when the coolant falls below the opening temp. And again reopen not at the 195 always but sometime not opening until say 205 or 210 and then again snaping open and the cycle continues. Buy a premium t-stat and you'll be glad you did.

You should look under the car after it sits a while and see if there is antifreeze on the ground. If so try to see where it could be leaking under the hood directly over the puddle. You could have a leaking water pump. If so there would be dampness under the right side of engine compartment. Also check the radiator hoses at front of car.

does the upper and lower hoses seem to be the same temp when car begins to overheat? ore the radiator cooling fans coming on before the car overheats? did you pressure test the cooling system and radiator cap? also may want to remove the lower hose and flush the radiator. is the check engine light on and does it run bad?

dear friend-there is a couple of things you can do to find the problem,when the engine is cold remove the radiator cap start the engine then look inside to see if the water is circulating,all so look for bubbles in the water,if there is bubbles,you might have a blown head gasket,if there is circulation the water pump is ok,then get the engine up to working temp,then feel both the top and bottom radiator they should be the same temp,if not then the termostat is at fault

try the fuse,if not that the wiring is bad from the fan to the switch.

I had trouble with overheating on my 2000 Grand Am, The dealer could not even resolve the issue,(they wanted to replace the intake gaskets)...I knew that was not the issue, no air leaks or water leaking there; so I sit down to think; what are the causes of overheating. Thermostat sticking - nope not it, water circulates, Water leak - nope not it, has water stays until it gets too hot and goes out overflow, fans working - yep...hummmm the only other thing I could think of was losing of water pressure, yep that's it - the cap on the coolant tank was going bad, got a new cap ($8.00) replaced the old one and no more trouble going on 6 months now.

Hope this may solve your issue.

If you have a white, milky fluid, you have moisture in the oil. No question on this. You may try retorquing the top of the engine (heads, intake, etc.). Change oil and filter. Now if this has electric motors for cooling (fans), make sure they are working. Don't overlook the obvious. Check the radiator cap. Cooling system must have pressure to function right. A bad cap could cause overheating.

Good Luck